Revert "Make sure grmlzshrc is only loaded once"

Revert "Make sure grmlzshrc is only loaded once"

This reverts commit 1dda332ef8a0fe126318794e6680e469e586835f.
This breaks interactively sourcing zshrc (wherever it is installed, or at all),
when it (or another version) was already loaded.

Another way of fixing the ".local is loaded twice" issue is under
discussion.